Displacement-based seismic design of buildings—theory

The conceptual basis of the spectral acceleration-based design method currently used in seismic codes is reviewed and its limitations are discussed. An alternative method that uses displacements as the basis for the design procedure is then presented. Its conceptual basis for elastic and inelastic seismic design and its application to single-degree-of-freedom and multi-degree-of-freedom structures are reviewed. The effects of torsion are considered. The advantages of this method over the spectral acceleration-based design method are also discussed. To the authorsʹ knowledge, this and the accompanying paper mark the first application of the displacement-based procedure to the seismic design of (steel) buildings.